Hello Sujeet,
To do this, variant table and dependencies have to be used.
1- create a variant table using t-code CU61 and add the characteristics, including "Special VAS code" and one more KEY characteristic, say "COLOR".
2- In table maintenance CU60, maintian the values for the Charceristic "Special VAS code" based on key characteristic , say, COLOR.. Give entries such that if COLOR is Black, then "Special VAS code" = 10, .. The characteristic COLOR need to be "Key" field.
3- Write Depenacny net, with CONSTRAINT, where you refer to the table, and infer values of "Special VAS code"
4- Add the Depedancy net to the Configuration profile of the Material number in CU41 or CU42.
Refer this sap help which explains the code and use of a constraint.
http://help.sap.com/saphelp_erp60_sp/helpdata/en/92/58c2f8417011d189ec0000e81ddfac/content.htm
Regards,
Aby